Oregon's deep blue sea is poised to be a new testing ground for green energy, as advanced technology has entrepreneurs lining up to try to harness the Pacific's wind and waves.

Last month, the Interior Department greenlighted the Pacific Coast's first offshore wind-power project, 18 miles off Coos Bay, Ore. Just to the north, another project would use energy-producing buoys to generate electricity from the up-and-down motion of sea...